Process of obtaining sound ingots.



No. 807,028. PATENTED DEC. 12, 1905. P. L. T. HEROULT. PROCESS OFOBTAINING SOUND INGOTS.

APPLICATION FILED JUNE 14, 1905.

INVENTOR:

/ WMQCMJMM%M,

WITNESSES:

mationof these pipes.

UNITED STATES PATENT OFFICE.

PAUL Lou s TOUSSAINT HEROULT, or LA PRAZ, FRANCE, ASSIGNOR TO soorn'rnELEGTRO METALLURGIQUE FRANQAISE, or FROGES, IsERE,

FRANCE.

Specification of Letters Patent.

Patented Dec. 12, 1905.

Application filed June 14,1905. Serial No. 265,174

To a, whom it may concern.-

Be it known that I, PAUL LoUIs Tons SAINT HnRoULT, a citizen of theRepublic of France, residing at La Praz, Savoie, France, have inventedcertain new and useful Improvements in the Process of ObtainingSoundIngots, of which the following is a specification.

It is well understood that in the casting of ingots-of steel there is atendency to form pipes along the central axis of the ingot, due to thesolidifying of the ingot first at the bottom and sides and thesubsequent contraction of the soft central portion in an outwarddirection. Hydraulic and other presses have been employed to compressthe ingots as they solidify in order to prevent the for- The process ofthis application is designed to replace such pressing-machines andaccomplishes the same result by cooling the outside of the ingot whilethe center is soft, causing the shell to contract and fill up the spaceswhich would otherwise be left in the center by the outward contractionof the metal. The cooling of the shell produces a contraction whichsqueezes the internal liquid steel toward the top of the ingot, and ifthe cooling is continued a sufliciently long timesay until the interiorhas become solidthe ingot will be sound in all parts. The cooling shouldbe eflected with a certain degree of carethat is to say, not too fast.The rapidity will be readily determined by a practical workman. Thecooling may be eflected by any suitable cooling fluid, such as a streamof water or a blast of cold air or gas. For example, any one of thefollowing methods may be used: The sides of the mold may be raised,leaving the ingot standing on its base, and streams of water may then beapplied on it, commencing at the bottom. The mold being removed, watermay be run into the pit in which the ingot is usuallycast, the depth ofwater being gradually increased. The ingot may be bodily lifted off itsbase and lowered into a bath. of water.

The accompanying drawings illustrate the method first above described.

Figure 1 is a central section through a partlycooled ingot in its mold.Fig. 2 is an elevation of the same ingot with the mold sides removed.

The ingot hardens at the bottom and sides witnesses.

gradually toward the center, the irregular lines A indicating roughlythe successive zones of solidification. When a sufficiently thick solidshell has formed to enable the ingot to stand alone, the interior beingstill substantially fluid, the mold sides B are lifted and jets of waterplayed upon the ingot C from hose-nozzles D or the like, commencing atthe base and working slowly up to the top. The cooling of the solidshell causes it to contract and to squeeze the fluid central portion soas to take up the contraction of such fluid portion, which would causeit to spread outward andform central pipes that is to say, the inwardcontractionof the shell counteracts the outward contraction of the fluidcentral portion. By commencing at the bottom and when the'interior ofthe ingot is very fluid the inward contraction of the shell will begreater than the outer contraction of the central fluid portion, and thelatter may be squeezed upward. It is not proposed to continue thecooling operation after the central portion of the ingot has hardened soas to be practically beyond the possibility of contraction, but only toapply the cooling action at such a rate and to such an extent as willcounteract the tendency of the central portion to form pipes or; voidsas it changes from a liquid to. a solid state.

Though I have described with great particularity of detail certainembodiments of the invention, yet it is not to be understood therefromthat the invention is limited to the specific methods described.Modifications may be made by those skilled in the art without departurefrom the invention.

What I claim is The process of making sound ingots which consists inrunning the metal into a mold, permitting the ingot to hardensufficiently to form a solid shell while the interior is stillsubstantially fluid, removing the mold, and applying a cooling fluid tothe shell of the ingot to cause it to contract upon the central portionso as to prevent the formation of pipes in said central portion.

In witness whereof I have hereunto signed my name in the presence of twosubscribing PAUL LOUIS TOUSSAINT HEROULT. Witnesses:

DOMINGO A. USINA, FRED WHITE.

